Urbanization refers to the process by which an increasing proportion of a population lives in towns and cities, driven by industrialization, economic opportunities, better infrastructure, and access to services. In recent decades, urbanization has accelerated rapidly, particularly in developing countries, transforming social, economic, and environmental systems. While urbanization contributes significantly to economic growth and modernization, it also generates complex environmental issues and sustainability challenges that must be carefully addressed. One of the most significant impacts of urbanization is environmental degradation. Rapid expansion of cities often leads to the conversion of agricultural land, forests, wetlands, and other natural ecosystems into built-up areas. This results in habitat destruction, biodiversity loss, and fragmentation of ecosystems. The removal of vegetation reduces carbon sequestration and contributes to climate change. Urban sprawl increases land consumption per capita, reducing green spaces and altering natural drainage systems, which can intensify flooding and soil erosion. Air pollution is another major impact associated with urbanization. Urban areas concentrate industries, vehicles, power plants, and construction activities, all of which emit pollutants such as particulate matter, nitrogen oxides, sulfur dioxide, and greenhouse gases. The heavy reliance on fossil fuels for transportation and electricity generation worsens urban air quality. Poor air quality leads to respiratory and cardiovascular diseases and contributes to global warming. The phenomenon of urban heat islands, where cities experience higher temperatures than surrounding rural areas due to concrete surfaces and reduced vegetation, further exacerbates climate-related risks. Water resources are also significantly affected. Rapid urban growth increases the demand for potable water while simultaneously polluting available sources. Untreated or inadequately treated sewage and industrial effluents are often discharged into rivers, lakes, and groundwater. Impermeable surfaces such as roads and buildings reduce natural groundwater recharge and increase surface runoff, carrying pollutants into water bodies. Many rapidly urbanizing cities struggle with water scarcity, contamination, and unequal distribution of water services, creating both environmental and social challenges. Solid waste generation rises sharply with urbanization. Growing populations and changing consumption patterns lead to increased production of municipal solid waste, including plastics, electronic waste, and hazardous materials. Inadequate waste management systems result in open dumping, burning of waste, and landfill overflows, contributing to soil, air, and water pollution. Poor waste handling also creates breeding grounds for disease vectors, affecting public health. Improper disposal of electronic waste releases toxic substances such as lead and mercury into the environment. Urbanization has significant social impacts as well. While cities offer employment opportunities, education, and healthcare, rapid and unplanned urban growth often leads to the formation of informal settlements or slums. These areas are characterized by overcrowding, inadequate housing, poor sanitation, and limited access to basic services. Social inequalities become more pronounced as